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Surely you remember the signs outside the local Chinese restaurants growing up. The ones that read, in bold letters, “No MSG,” signaling that their menus were free of that dreaded ingredient, so it was perfectly safe to eat there. At some point, MSG was stigmatized, with many Americans declaring they try to avoid it as much as possible and citing migraines, nausea, bloating, brain fog, and other symptoms of discomfort. But are these symptoms backed by fact, or is it a case of tarnished reputation? Lately, MSG is getting a bit of a PR makeover, with professional chefs singing its praises, which piqued our interest.

We’re breaking down what MSG is, how it was discovered, and how it got such a bad rap — plus a handy “Fact vs. Fiction” section on consuming MSG to make it all easy to digest. (Pun intended.)

Click HERE to skip straight to Fact vs. Fiction!

What is MSG?

Monosodium glutamate (MSG) is a flavor-enhancing odorless crystalline white powder added to foods to make them taste more umami. Umami is the fifth taste that “officially” joined bitter, sweet, salt, and sour in 1990. However, it has been around for much longer and is thought to be an evolutionary sort of taste. You see, umami is a savory/meaty/protein taste not necessarily found in meat. It comes about when foods are ‘cooked’ in some way — that is, dried, aged, cured, heated, or fermented.

Scientists believe that the detection of this umami taste developed for these reasons. For example, heating food kills bacteria and makes it easier to eat and digest. Similarly, the fermentation process produces friendly bacteria that are good for our bodies and crowd out harmful ones in the gut. And so, the treatment of food makes it more palatable, tasty, and safe — an evolutionary bonus!

When you taste umami, which is the detection of glutamate, your mouth waters, and these salivary secretions enhance food flavor. It makes eating umami food more pleasurable.

Close up of Monosodium glutamate (MSG), a flavor enhancer in many asian food
Most of us have never actually gotten a look at MSG. Up close, it looks a lot like sugar!

With a name like MSG, no one would blame you for thinking this additive is manufactured artificially. However, MSG is produced through fermentation just like beer, yogurt, and kimchi. Fermentation is the chemical breakdown of a substance using bacteria or yeast to convert carbs (sugars) into acids, gas, or alcohol.

This 10,000-year-old process, which is also used to make wine, extracts energy from carbohydrates in the absence of oxygen. So although it is made under laboratory conditions, it actually comes from fermenting starch, sugar beets, sugar cane, and molasses. The FDA categorizes it as GRAS: generally recognized as safe.

There are other umami substances besides monosodium glutamate (MSG), such as inosine 5’-monophosphate (IMP) and guanosine 5’-monophosphate (GMP), which you’ll often find in processed and canned foods, soups, sauces, and dried bouillon cubes. IMP is also used as a flavor enhancer, in addition to MSG, to further accentuate its umami taste.

How was MSG discovered?

Aside from being produced in the body, glutamate is found naturally in some foods that most of us eat often, such as tomatoes, cabbage, and mushrooms, as well as foods that have been around for a very long time, such as cheese.

In fact, its presence in nature is what led to its discovery.

In 1907, Kikunae Ikeda, a professor at Tokyo Imperial University, embarked on a journey to find the elusive umami component in kelp, an edible seafood found commonly in Japanese cooking. He got this idea after eating a particularly tasty soup made by his wife, and his intention was to improve human nutrition. Within a year, Ikeda successfully isolated, purified, and identified the principal component of umami, earning himself a patent for the process.

side view of steaming noodle soup in black bowl
Never underestimate the power of a good soup! The creation of MSG was inspired by a particularly delicious soup prepared by the inventor’s wife.

In partnership with entrepreneur Saburosuke Suzuki in 1909, Ikeda began the industrial production of monosodium L-glutamate (MSG). It wasn’t until the 1950s that better methods with significant advantages emerged. One of these was a direct fermentation method, introduced in 1956, which reduced production costs and environmental load, resulting in all glutamate manufacturers shifting to fermentation. Today, glutamate’s global production by fermentation is massive, at a whopping two million tons per year.

So, knowing all that, how and when did MSG come to be seen as something to avoid? Research shows that a good portion of the population actively avoids MSG by scouring food labels or restaurant menus. And yet, it is not a banned additive. So, what’s the deal? Is it hazardous?

MSG’s Reputation

MSG’s reputation took a hit in the ’60s when Chinese-American Dr. Robert Ho Man Kwok reported getting sick after eating Chinese food. In his letter to the New England Journal of Medicine, he speculated that alcohol, sodium, or MSG may have caused his symptoms. Unfortunately, this only fueled existing prejudices against the quality of ingredients in Chinese cuisine, perpetuating misinformation about MSG. Kwok’s letter led to other similar observations at the time.

friends eating chinese takeout together
In the ’60s, a stigma began to develop surrounding MSG, an ingredient often used in Chinese cooking at the time. This stigma had unfortunate consequences for Chinese restaurants — and as the facts would suggest today, the fuss over MSG was unnecessary.

However, current evidence casts doubt on previous research for several reasons: inadequate control groups, small sample sizes, methodological flaws, imprecise dosing, and exaggerated doses that exceed those in typical diets. Additionally, previous studies used administration methods (such as injections) irrelevant to the general population — realistically, people only consume MSG orally.

While older research — and unfortunate racial bias — implied that MSG was toxic, current health authorities and evidence recognize it as safe.

In addition, even if you think you’re avoiding it by looking for that “No MSG” sign, you may be misled. MSG is known and labeled under various other names (especially when it is naturally occurring), such as yeast extract, glutamate, E621, hydrolyzed protein, autolyzed yeast, soy extract, protein isolate, sodium caseinate, and calcium caseinate. With MSG occurring in natural foods (even breast milk!), obliterating it from our diets is difficult.

It might also be futile. Since there’s no chemical difference between the glutamic acid found naturally in some foods and that in MSG, the compound is not metabolized any differently in the body.

Fact vs. Fiction: The Health Impact of Consuming MSG



  • MSG is always manufactured in a lab.
  • The body recognizes MSG that is not naturally occurring.
  • Any amount of MSG is bad for you.
  • MSG increases salt intake because it breaks down into sodium and glutamate.
  • Manufacturers can use different names for MSG and declare their food to be free of MSG.
  • MSG is a trigger for all migraine sufferers.
  • Celiac sufferers and gluten-sensitive people should avoid MSG.
  • MSG can alter brain function, leading to toxicity in brain cells, over-excitation, and cell death.

The Last Morsel

Having said all that, this doesn’t exclude that some people may be sensitive to glutamate. For those that are sensitive (a small percentage of the population), migraines, brain fog, bloating, and nausea may, in fact, be associated with the consumption of relatively high amounts of glutamate. The number of people genuinely sensitive to MSG has been suggested to be around 1 to 2% of the population.

Just like salt, the level of MSG is regulated in foods, and while high salt consumption can lead to high blood pressure, it is challenging to consume MSG in amounts that will cause adverse effects. In one typical meal with added MSG, the average person will consume 0.5 grams of it. Toxic effects are thought to start when someone consumes 3 grams of MSG alone (not within a dish).

So, while we certainly wouldn’t suggest prioritizing it in your diet, we’re dropping our old, negative misconceptions about MSG. Nothing wrong with a little umami, right?


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About the Author
Miriam Calleja